Insects are the most numerous and diverse animals on earth, constituting about 80% of all described animals. They are generally characterized by six legs, four wings, and bodies divided into head, thorax, and abdomen. They include grasshoppers, beetles, bugs, dragonflies, bees, ants, flies, cockroaches, and butterflies. Insects perform essential roles in all ecosystems, including pollinating most flowering plants and recycling organic matter.